Effect of Injection Timing on Performance and Emission of a Diesel Engine using Fuelled by Hydrogen Gas

The injection timing of pilot fuel in diesel engine working on dual fuel mode with gaseous fuel is a very important parameter at the start of ignition which affects performance and emissions of the engine. In this regard, the experiments were conducted on single cylinder 4-stroke, direct ignition diesel engine with a power of 3.50 kW at a constant speed of 1500 RPM. Kirloskar model TV1 with diesel as pilot fuel and hydrogen as gaseous fuel was employed. Experiments were conducted with the aim to determine the effect of advancing (21o bTDC) and retarding (17o bTDC) diesel fuel injection timing on the engine performance and emissions at various load conditions with the standard injection timing of 19o bTDC. The brake thermal efficiency (BTE) and exhaust emissions like NOx, carbon monoxide (CO), carbon dioxide (CO2) and hydrocarbon (HC) were analyzed with hydrogen (H2) as gaseous fuel. The results showed that dual mode (diesel and H2 gas) retards injection timing (17o bTDC) and gives a net increase in BTE efficiency at all load conditions with lower (20%) hydrogen substitution. At higher H2 substitution (40%), BTE is better for dual standard (19o bTDC) injection timing at all load conditions. Further NOx (ppm), HC (ppm), CO (%) and CO2 (%) emissions are significantly reduced with dual retard (17o bTDC) injection timing of the pilot fuel.